1. Field of the Invention
This invention relates generally to stenciling equipment and more particularly is directed towards a new and improved apparatus for stenciling identification indicia by air driven abrasive particles onto a window of a motor vehicle or the like for purposes of inhibiting the theft thereof.
2. Description of the Prior Art
There has developed in recent years a new technique for reducing the risk of theft of various products, especially automobiles. The technique has involved the etching of an identifying code number onto the windshield of the vehicle. Code systems are utilized in conjunction with central registries so that, if an owner of a marked car needs to be identified, it is a simple matter to check the code number which has been etched onto the glass of the windshield and all other windows with a central registry in order to identify and locate the true owner of the vehicle. Because of the time, difficulty and costs involved either in obliterating or altering the identification number on the windshield or in replacing the entire windshield, thieves are deterred from stealing vehicles which are so marked.
Equipment currently available for etching an identification code on windshields or other glass areas have involved gun-like devices that are connected to a source of compressed air and are adapted to direct a stream of abrasive particles against a stencil located at the head of the gun and which is placed against the glass surface to be marked. While the technique of using a stream of abrasive particles to etch glass or other hard surface with an identification code of other indicia has proven to be a successful deterrent to theft, there do exist certain problems with respect to the stencil head of the gun employed for this purpose. These problems have generally involved the production of stencils of sharp outline and a head and stencil configuration which permits quick and easy changing of stencils in order to change code numbers rapidly. Other problems have developed with respect to small leaks between stencils which produce spurious markings on the glass surface.
Accordingly, it is an object of the present invention to provide a new and improved stenciling gun for use in etching identification indicia on glass surfaces or the like wherein stencils of sharp outline can be quickly and easily changed.
Another object of this invention is to provide a head assembly for abrasive stenciling guns in which one or more sets of identification stencils may be quickly and easily assembled without leakage between stencils and of a configuration which prevents improper mounting of individual stencils.